Input current/ Power Measurement

[smart_life]

Hey everyone,

I have measured input current by different transmit powers:

nRF52840

Equipment: Konstanter ssp 240-40 as current source

Agilent 34401Afor current measurement

Software: modified light switch server witch can send beacons (advertisement packets each 20ms)

Measured value is the Input current on  the external input of the nRF:

 -40dBm=100nW: 3V : 12,6505mA

 0dBm=1mW:: 3V: 12,72756mA

+8dBm=6,3mW: 3V: 13,13473mA

I can not understand the values I get: If I change the Tx Power from almost zero to 6,3mW I would expect that the Input current changes also by (6,3mw/3V=2,1mA) but I measure  current difference approximately 0,5mA. That means that the assumed Tx-Power what I set in the software is not the real one (why ?) or do I measuring something wrong ? 

[WestCoastDaz]

No I don't think your measurements are wrong, like the DC/DC is enabled which is doing exactly what it's supposed to do which is provide efficient regulation to the processor and reduce the overall power consumption.  Look at the this section of the Product spec Power